Page:The New International Encyclopædia 1st ed. v. 14.djvu/667

* NILE. 567 NILE. reason the maximum Hood at Cairo appears only about (Jftober 1st. The rains cease in .M)yssinia about the middle of Septemlier, the llooils of the lilue Nile and the Atbara disaii|)wir, and then the great lakes and marshes of Central .friea are the main sniijily of the river until the foUowing June. This routine of the waters is marki'd by marvelous regularity. The time between an early and a late Hood is not more than three weeks. The height of the Hood at Assuan is usually about 25 feel above the minimum supply. If the water rises 29 feet alwve the minimum, the crops of Egypt are in danger. If it rises only 20 feet above the minimum, large ai'eas cannot be flooded. The mean Mood discharge at Cairo is about 2S0.000 eubie feet per second (about equal to the average How of the Niagara River), the maximum about 400,000 feet. The general slope of the valley on each side is away froni the river. Along each edge of the river is an earthen em- bankment too high to be topped l)y the Hoods. Along the valley is a series of embankments, one end of which is at the river edge and the other on the sides of the hills that wall in the valley. The whole country is thus divided into a series of oblongs surrounded by artificial embankments on three sides and by the slope of the desert hills on the fourth. There are 120 of these oblongs, varying in extent from 60,000 to about 3000 acres. It is easy to cut short, deep canals in the banks which fill as the flood rises and carry the nuid-charged water into these basins of irriga- tion. There the water remains for a month or more, .three to four feet deep, depositing its mud. At the end of the Hood the water is passed off through sluices from one basin to another and ultimately back into the river. In November seed is sown, and so saturated is the soil that the grain sprouts and thrives and the harvest is gathered in April or May without a drop of rain or any fresh irrigation. After the crop is reaped the fields remain dry and cracked in the fierce summer heat until the next Hood comes on. A little below Cairo is a great dam or barrage across the river, by means of which all available water in the Nile before it begins to rise in June is diverted into canals that carry it to the cott(Ui fields of the Delta. This barrage makes it possible to irrigate Delta crops in the dry sea- son, so that to a large extent two cro])S a year are raised there. The water in the Delta would not be sullieient if a strict system of control were not maintained by which each cultivator is sup- plied in turn every fifteen or twenty days. The great need has long been to store the waters during Hood time (when a large part of them run to waste) so that the.v miglit be turned over the fields during the months of low Nile, lliiis giving to Egypt the benefits of irrigation at all seasons, and making it possible to raise two or three crops annually where only one or two were grown. Near Assuan, the gateway to Lower Eg^-pt, the work on the great and mudi desired reservoir was begun. It was compUded and formally opened in December, 1002. The work consists chicHy of an enormous wall or dam. of masonry nearly 2 miles long and averaging flO feet in height. The wall is ])iereed by ISO open- ings, each containing sluices through whieli the low Nile may pass and the retained flood waters may escape a.»i they are needed for irrigation. A roadway runs along the top of the wall. It is estimated by Sir William Garstin that the vol- ume of water impounded by the dam will reach the enormous total of ;i7,l>12,17!),000 cubic feet. He estimates also that in the distribution of this reserve supply 70,000 ai'res in Upper Egj'pt, be- tween Assuan and Assiiit, will receive perennial irrigation; also 458,000 acres now irrigated as basins in Middle Egjpt between Assiut and Cairo; that, further, 52,000 acres in the Fayum now unfilled may be reclaimed; and that in Low- er Egj'pt or the Delta the a<lditional water will insure the cotton crop against drought, and re- claim an area of 120.000 acres now uncultivated. In the Province of (Jhi/.eh likewise an area of lOti,- 000 acres of basin cultivation will be converted into [lerennially irrigated land. Since the dam at Assuan closes the Nile to navigation, a canal 0540 feet in length with four locks is being constructed around it. Mail steamers and any stern wheeler now on the Nile may pass through the canal, and sailing vessels may pass Assuan all the year round, thoiigh heretofore they have been able to get through the cataract only during high Nile. Below Assuan a barrage has also been constructed at A.ssiut for the purpose of raising the level of the river in summer, so that water may be de- livered at that point at a higher level, increasing the discharge into the Ibrahimia Canal, which carries the supplies to the basins as far north as IMinieh and Beni-Suef. These great works will add enormously to the productivity of Egj'pt, will increase the value of all the farm lands, and will augment the revenues of the Government. See Egypt and Egyptian Sudan. Bibliography. Most of the information on the Nile is scattered through oHieial publications and books relating to Egypt, the Anglo-Egyptian Sudan, and the Lake Region of Central Africa. Among these are: Bruce, Travrlt to Disrorer the SoHrecs of the Nile (3d ed., London. 1S13) ; Beke, The Sources of the Nile (ib.. 1800) ; Speke, Jour- iiril of the Discovery of the Source of the Nile (ib., 1803); Baker, The Nile Tributaries of Abyssinia (ib., 1S07); id., The Albert Nyaiizn, (Sreat Basin of the Nile and Exploration of the Nile Sources (ib., 1871); Chavanne, Afrikas Htriime und Fliisse (Vienna, 1874) ; Schwein- furth. Heart of Africa, trans. (2d ed.. London. 1875) : Ebers, Aegypten in liild und Wort (Stutt- gart, 1879; trans, as Eyypt. Dcscriplire. His- toriral, and Pirtiiresi/ue, London, IHOS); Poole, Efjypt, in "Foreign Countries and British Colonies Series" (ib., 1881); Hartmann, Die NiWinder (Leipzig, 1884) ; Edwards, A Thousand Miles Up the Nile (London. 1889) : Willcoeks, Egyptian Ir- rigaUon ( ib., 1889); .Tunker, Travels in Africa, trans, (ib.. 1890-92) ; Budge, Dwellers on the Nile (ib., 1890) ; Chehi, Le Nil, le Soudan, I'Efiypte (Paris, 1891); Baumann, Purrh ^fa.s- sniUrnd sur Nilquelle (Berlin, 1894) ; C.essi. Sette anni nel Sudan erjixiano (Milan. 1891) ; Report on Perennial Irrigation and Flood Protection for Egypt (Cairo, 1894) ; Ucporl on the Nile and Country Between Dongola. Sual'in, Kassnhi, and Omdurnian (2d ed., London, 1898) ; Stulilmann, Mil Emin Pasha ins Hers von Afrika (P.crlin. 1894) ; Colville, The Land of the Nile Springs (London, 1895) : Brown and Carstin, History of the Barrage at the Head of the Delta of Egypt (Cairo. 1896) ; Wood, Egypt Under the British (London, 1896): Notes on Egyptian Crops (Cairo, 1890); Casati, Ten Years in Equnfnria (London, 1898) ; White, The Expansion of Egypt